Rotary compressor



W, w23, M. BALCKER ROTARY COMPRES S OR Filed March 28 19.21 2sheets-shee-a 1 ROTARY COMPRESSOR Filed March 28 1921 2 Sheets-Sheet 2 Ml N A a 'Patented Apr.. il?, lZ.

MARTEN BALCKEB., OF CHICAGO, ILLINOIS, ASSIGNUR T0 JOHN NELSON, OFCHICAGO,

- ILLINGES.

normar comraiesson.

Application led March 28, 1921. Serial No. 456,416'.

To alt/whom t may concern:

Be it known that I, MARTEN BALoKnR, acitizen of the United States,residin at Chicago, in the county of Cook and tate of Illinois, haveinvented certain new and useful improvements in Rotary Compressors, ofwhich the following is a speciication.

This invention relates' in general to compressors adapted to compressair and other fluids, and pertains more particularly to the typecommonly known as rotary com-- pressors.

One of the primary purposes of my present invention is to provide acompressor of this type, which will eii'ectually preclude leakagefromthe delivery side back to the intake side of the compressor, therebyresulting in a compressor of high eiiciency which is capable ofproducing higher pressures than can customarily be obtained with rotarycompressors heretofore manufactured.

Another purpose of my invention is to provide for adequate and effectuallubricaltion of the moving parts so that they will not stick and toinsure this lubrication by delivering the oil under the pressureexisting at the delivery side of the compressor so that the pressure ofthe oil is increased pro ortionat'ely to the work being performed y t ecompressor.

A further object of the 'invention is to provide a com ressor which willconsist of few parts, so t at it can be cheaply manufactured and readilyassembled, and one which will not be liable to get out of order, andwhich will be eilicient and extremely durable.

Other objects and many ofthe inhereit advantages of this inventionshould be readily appreciated as the same becomes better understood, byreference yto 'the following description when considered in connectionwith the accompanying drawings.

Referring to the drawings:

Fig. 1v is a transverse sectional view through a compressor embodying myinvention; and

Figs. 2 and 3 are longitudinal vertical and horizontal sectional viewstaken on the lines 2--2 and 3-3 respectively of Fig. 1.

Referring nov:r to the drawings more in detail, reference character 5indicates generally the casing 4of my improved compressor, the casingbeing of any preferred construction, but' for convenience ofmanufacoverlies the margin of the end 7 and threaded intotapped openingsin the opposed face of the body member. Asuitable gasket 11 1spreferably interposed vbetween the ring 8 and the faces against which itlies to insure against leakage at thisjoint.

The end walls of the casing are shaped to form bearings 12 and 13respectively, in which the shaft 14.- of the rotor 15 is journaled, andalso to provide bearings 16 and 17 respectively directly beneath therotorl shaft in which the shaft 18 of the sealing device 19 isjournaled.' The bearings 12 and 13 are equipped with suitable bushings21 and the end ofthe bearing 12 is referably closed by a plug 22 whichpreclu es leakage of oil at this point. The opposite end of the shaft 14extends outwardly beyond the bearing 13 for connection to fany suitablesource of power by which the rotor is driven and leak- -age around theshaft at this end is prevented by a packing gland 23 of any approvedconstruction. Similarly, the end of bearing 17 is closed b .a plug 24and leakage around the projecting end of shaft 18 at'the opposite end ofthe casing is precluded by a packing gland 25.

The rotor 15, as will be apparent from Fig. 1, is of generallyelliptical'shape in transverse cross section, and the vupper por- Vvtionofthe casing,V indicated by reference poses, this upper portion of thecasing' is preferably equipped with radiating ribs 28 to dissipate theexcess heat produced by the operation of the machine.

The casing is also formed to provide at one side, the intake passage 29and at the opposite side, to provide the delivery passtruction.

sage 31. The delivery pipe 32 connected to this passage, is providedwith a check valve 33 of usual or any preferred con- While the upperportion of the casing substantially fits the rotor, as previouslyexp1ained,. the lower portion is enlarged to provide an oil chamber34,and directly beneath the rotor, this chamber is interiorly curved toprovide a pocket or recess 35, in which the arcuate outer wall of thesealing device 19 Vsnugly but slidingly lits. This oil chamber may befilled with oil by removal of the lling plug 30, and the normal oillevel 'in the chamber is shown in Fig. 1, The chamber may be drained ofthe oil whenever necessary by removal of the drain plug'40.

It will be observed that the delivery passage 31 is simply the. upperportion of the oil chamber 34, and consequently, 'the pressure producedin this passage by the operation of the rotor is exerted directly uponthe oil in this chamber so that the pressure of the oil is exerted uponthe sealing device or blade 19. From Fig. 1,it will be observed that theupper radius of this device is shorter than the lower radius, or, inother words ,that the distance from the center A to point yB is lessthan the distance from the center A to point C. The area of thelsurfaceAC exposed'to the oil pressure is therefore greater than the area AB,with the result that the upper edge of .the sealing device is urgedagainst and in contact with the rotating perimeter of the rotor 15toprovide a Seal at this point which divides the intake passage from thedelivery passage, and obviously, the pressure exerted on this line' ofcontact is directly proportional to the pressure created in the deliv`-ery passage 31. This seal therefore -prevents the escape of air fromthedelivery back to the intake side of the machine below the rotor, andleakage of air at this point is further insured against by the fact thatthispoint is always submerged in the oil s0 that no air canobtain accessto the jecting laterally from an arm 39 which is vfixed by a pin 41,or'otherwise, to the projectingend of the blade shaft 18, as will beapparent from Fig. 2.

From Fig. 3 it will be observed that the l delivery passage 31 is opento the periphery of the rotor thru a port of large area between theinwardly projecting walls or ribs '42 and 43,'which are provided forleakage prevention, but the intake passage 29 at the opposite side ofthe machine communic'ates with the rotor through -a long, but relativelynarrow port 44, the areaof which, however, is substantially equal to thecross sectional area of the intake passage 29. Inwardly of this port 44and between the port and the upper end of the sealingdev'ice 19, thechamber extends the full length of the casing so that air enteringthrough the port when the short radius Vof the rotor i's opposite theport, will fill the chamber and be trapped ahead of the following longradius of the rotor, and carried thereby around and above the rotor tothe delivery side of the casing. While -the sealing device 19 willclosely hug the perimeter of the rotating rotor as the same travels in aclockwise direction, viewing Fig. 1, nevertheless, the direction oftravel of the rotor and the irregularity in its lcontour will cause asmall quantity of oil to leak past the sealing device into'the chamberat the left hand side thereof, viewing Fig. 1, and immediately beneaththe port 44; Since the oil in this chamber will extend from end to endin the casing, and since the port 44 is relatively narrow, it will beobvious that -avportion of thispil will be picked up by the long'radiusportion of the rotor and carried with the air also trapped above theoil, around to the delivery side of the casing. Centrifugal force willcause this trapped oil tocollect at the outer end of the rotor, asindicatedby reference character 45 (Fig. 1), and this oil therefore,forms a seal between the rotor and the concentric upper portion of thecasing so as to efectually preclude leakage of air back past the rotorat its perimeter. All of the air trapped in the upper portion of thecasing will therefore be delivered, together with the oil seal, into thedelivery passage 31 of the casing, Where the oil will collect in the.chamber 34, while the air will be delivered under pressure through'. thepipe 32. At e-ach half revolution of the rotor, therefore, a smallquantity 0f oil will be displaced under pressure from the right handside to' the left hand side, viewing Fig. 1 of the sealing device 19,and atthe same time, this displaced oil will be picked up by the rotorand returned to the ldelivery sideV of the casing` the oil serving inits return passage as a liquid seal betweenthe rotor-and the casing toprevent leakage of air. It will thus be apparent that both the upperandlower sides of the rotor are eectually sealed by oil against leakage ofair from the delivery to the intake side of the casing. p

For the purpose of preventing leakage of, air past the ends of therotor, I.. have also provided for an oil seal at these ends, and forthat purpose, leach end of the rotor is provided with a plurality ofradially disposed v Merate grooves 46 and 47, the grooves 46 beingdisposed on the short radius and the grooves 47 on the long radius ofthe rotor. The outer ends of these grooves are closed, as shown, and theinner ends of grooves 46 at opposite ends of the casing are connected bypassageways 48, while similarly, the grooves 47 at opposite ends of therotor are connected by passage-ways 49. All of the radial grooves ateach end of the rotor are also connected by an annular groove 51 so thatoil delivered to this groove will be thrown by centrifugal force intothe radial grooves, thus keeping them filled with oil to form seals atthe ends of.the rotor.

The oil is supplied to these sealing rooves under pressure from the oilcham er 34 through a suitable passage which, in the present instance, isformed in the end wall ofthe casing and comprises an inclined portion 52opening at its inner end into the opposed groove 51 and closedat itsouter end by a plug 53, a second passage 54 opening at its upper endinto the passage 52, and closed at its lower end by a plug 55 and alateral passage 56 extending from the passage 54 into the chamber 34.rlhese passages are shown in dotted lines in Fig. 1 for purposes ofclarity, although strictly, they would not appear in this figure. Itwill be apparent, therefore, that oil will be delivered under pressurefrom the chamber 34 to the grooves at both ends of the rotor, and alsoto the bearings for the rotor shaft 14. keeping these bearingsthoroughly lubricated, and at the same time. keeping the sealing groovesfull of oil under pressure, resulting from the pressure exerted on theoil in the chamber 34, and also from the centrifugal force exerted uponthe oil and the `grooves themselves by the rotation of the rotor. Aneffectual oil seal is therefore provided'at each end of the rotor, whichvprecludes leakage of air past the ends of the rotor, and since both thetop and bottom,

of the rotor are also eii'ectually oil-sealed, as previously explained,it will be apparent that the oil seals around the perimeter and at theends of the rotor effectually preclude anv leakage of air from the highpressure deliveryv side to the low pressure intake side of the,compressor.

lt will be apparent from the foregoing that l have provided a compressorwhich comprises only two moving parts, namely, the rotor and the sealingdevice: that the rotor is etfectually sealed by an oil seal underpressure against leakage. and that the, device is at all timesthorough-ly lubricated by oil bodiment, it should be obvious that theinvention may be incorporated in structures differing materially intheir detalls of construction from that shown and described,

without departing from the essence of the invention as defined in thefollowing claims.

I claim: 1. A compressor, comprising a casing provided with inlet anddelivery passages, an elliptical rotor in said casing, a pivoted sealingmember engaging the lower portion of said rotor, an oil seal in whichsaid sealing member and the lower portion of said rotor are submerged,and means for maintaining an oil seal between said casingand the endwalls of said rotor, said sealing device having a portion exposed to thepressure of said oil seal whereby close contact is maintained betweensaid sealing device and the periphery of said rotor.

2. A compressor, comprising a casing provided with inlet and deliverypassages, a portion of the casing below said passages being shaped toform an oil chamber, a rotor mounted in said casing concentrically withthe upper portion thereof with its lower p'ortion submerged in the oilin said chamber. and a sealing device pivotally mounted in said oilchamber in position to engage said rotor, said sealing device presenting'a surface to the oilin said chamber under the pressure of the deliveryside of the compressor whereby said device is maintained by saidpressure in engagement with said rotor.

portion of said casing being concentric with the rotor and the lowerportion being shaped to provide an oil chamber, inlet and deliverypassages communicating with said chamber above the oil therein, apivotally mounted sealing device disposed beneath said rotor andsubmerged in the oil in said chamber, said device having an area exposedto the 'oil under thc pressure of the delivery side of thel casingwhereby said device is rocked on itspivot into' engagement with theperiphery of said rotor, means for maintaining an oil seal between theupper portion of said casing and the perimeter of the rotor, and meansfor maintaining an oil seal under the pressure exerted upon theoilwithin said easing between the end walls 'of said casing and theopposed end faces of said rotor.

4. A compressor, comprising a casing prod. A compressor, comprising acasing, an elliptical rotor mounted therein, the upper lou vided atopposite sides with intake and delivery passages respectively, a rotorin said casing, and means .for maintaining a liquid seal under pressurebetween the intake and delivery sides of said casing. 4

5I A compressor, comprising a casing provided with intake and deliverypassages at 'opposite sides thereof, a rotor rotatably mounted withinsaid casing, the upper portion of the casing being formed concentricaliywith. the axis of rotation of said rotor, and means for maintaining .aliquid seal between the opposed faces of'said rotor and casing. t

6. A compressor, comprising a casing providing an oil chamber in thelower portion thereof, an integral elliptical rotor mounted therein andpartially submerged in said chamber, grooves formed in the ends of saidrotor, passages through the rotor connecting the grooves at the ends 'ofthe rotor, a sealing device submerged in said chamber and engaging theperimeter of said rotor to 4seal the outlet from the inlet of thecasing, and a passage for delivering oil under pressure from saidchamber to the grooves and passages of said. rotor to eii'ect an oilseal bletween the' ends of said rotor and the opposed end walls of saidcasing. Y

7. A compressor, comprising a casing, an elliptical rotor mountedin saidcasing, the upper portion ofvsaid casing being formed concentricallywith the axis of rotation of the rotor and the lower portion beingformed to provide an oil chamber, an inlet passage communicating withone side of said chamD ber, a delivery passage communicating with vtheother side thereof, a sealing device submerged in said chamber beneaththe rotor and constructed to be maintained in contact with said rotor bythe pressure in the delivery side of the casing, said rotor beingprovide an oil seal between said rotor and the casing.

8. A compressor, comprising a casing provided witli. intake and deliverypassages, an oil chamber connecting said passa es, a sealing devicedisposed in said oil c amber, a rotor mounted in said casing and adaptedto peripherally Contact with said sealing device, and means forsupplying oil under pressure from said chamber to the ends of said rotorto maintain an oil seal between said ends and the end walls of thecasing7 said casing being so shaped that oil in the intake side of saidchamber will be carried by said rotor to the delivery side thereof.

9. A compressor, comprising a casing providing an oil chamber in thelower portion thereof, an elliptical rotor mounted in said casing, andpartially submerged in the oil in said chamber, the ends of said rotorbeing provided with radially disposed grooves, a connection through therotor between the grooves at opposite ends of said rotor, a sealingdevice submerged in said chamber and a passage through which oil issupplied under pressure produced by said rotor from said chamber to saidooves.

' l TEN BALCKER.

